A conventional semiconductor integrated circuit is composed of transistors formed on a semiconductor substrate, and an interconnection structure, formed as an upper layer of the semiconductor substrate for interconnecting the elements. The interconnection pattern is determined at the designing stage of the integrated circuit, and hence the connecting states of the transistors cannot be changed after the fabrication of the semiconductor integrated circuit.
The above problem can be solved with a programmable semiconductor integrated circuit, such as FPGA (field programmable gate array). With the programmable semiconductor integrated circuit, the function of the logic circuit or the arithmetic circuit, and the interconnection between the logic circuits and/or the arithmetic circuits, can be changed based on stored information of memory devices to enable the logic/arithmetic functions or the interconnection between them to be reconfigured as desired. As the memory devices for storage of the configuration information, an SRAM (static random access memory) cell, an antifuse or a floating gate MOS transistor, is used.
A DRAM (dynamic random access memory) cell or a ferroelectric capacitor may also be used.
[Patent Publication 1] U.S. Pat. No. 6,487,106